Thunderbolt 3 Merges With USB to Become USB4

By
Tom BrantMarch 5, 2019, 3:26 a.m.

The new USB4 protocol could be a single port to rule them all, but it probably won't make life any easier for shoppers poring over specs.

If your new laptop or desktop PC features a Thunderbolt 3 port, congratulations! This do-it-all connector can link virtually any peripheral—even ones that are daisy-chained together—at astonishing speeds of up to 40Gbps, all while delivering enough power to charge batteries, too.

But Thunderbolt 3 is a proprietary spec that belongs to Intel, which until recently limited PC makers' ability to include it in their products without paying royalties. So your new laptop or desktop PC might not feature a Thunderbolt 3 port after all, unless it's a premium model. All Mac laptops have them, and Intel says about 400 PC models have them, but that still leaves many PCs out, especially cheaper ones.

The good news is that Intel has long promised that it will eventually make Thunderbolt 3 royalty-free, and on Monday we finally got a glimpse of how that will happen: Thunderbolt 3 is merging with USB.

Specifically, it will be baked into a brand new version of USB, called USB4. It's a welcome development, though it adds yet another spec name to an already-crowded field of USB specs that laptop and desktop shoppers must consider.

USB4, scheduled for release this year, will include the best parts of both Thunderbolt 3 and USB-C. That means 40Gbps data transfers for external storage drives, eight times the speed of the USB 3.0 interface. It also means the ability to output display signals for external monitors, as well as deliver power to charge small devices (phones and tablets) and large ones (laptops).

The new USB4 port will also be more capable than current Thunderbolt 3/USB-C combo ports, according to the USB Promoters Group, an industry association made up of Apple, HP, Intel, Microsoft, and other companies. Improvements could enable a "doubling of performance," the group said in a statement, while maintaining backwards-compatibility with USB 3.2, USB 2.0, and Thunderbolt 3.

If USB4 is taking the best technologies from today's ports and putting them into a single connector that could be included on even the cheapest PCs thanks to the abolition of royalty payments, then all you need to look for in your next PC purchase is a USB4 port, right?

I hope that will be the case, but it's not likely, because the separate Thunderbolt 3 and other USB standards aren't going away. In fact, Intel plans big things for Thunderbolt 3, such as integrating it into the chipset for its next-generation "Ice Lake" CPUs. So you'll likely still see advertisements for Thunderbolt 3 ports for years to come.

The same thing applies for other types of USB ports. Just last week, the USB Implementers Forum (a separate industry association from the USB Promoters Group) announced that it's overhauling the USB naming conventions. That means the older USB 3.0 standard, which offers 5Gbps speeds, will now be called USB 3.2 Gen 1. Meanwhile, USB 3.1, which offers 10Gbps speeds, will be rebranded USB 3.2 Gen 2. The 20Gbps USB 3.2, on the other hand, will be called USB 3.2 Gen 2x2.

All of these port specifications will be available to manufacturers in addition to the new USB4 port. Which means that next year, in a kitchen sink mashup, shoppers could potentially be looking at a cutting-edge PC with Thunderbolt 3 support baked into the CPU, in addition to USB4 and USB 3.2 Gen 2x2 ports.

There's also the prospect of certain PC and peripheral makers going rogue and using their own naming conventions and even color-coding different ports in different ways. For instance, today most (but not all) Thunderbolt 3 ports are labeled with a Thunderbolt logo, and most USB 3.0 ports are blue, though some (on Razer laptops, for instance) are green.

Ultimately, relinquishing control over Thunderbolt 3 is indeed a "significant milestone for making today's simplest and most versatile port available to everyone," as Intel General Manager for Client Connectivity Jason Ziller said in a statement. But while the port itself may be simple, it probably won't make it any easier for shoppers to decide which connections their next PC should have.

About the Author

Tom is PCMag's San Francisco-based news reporter. He got his start in technology journalism by reviewing the latest hard drives, keyboards, and much more for PCMag's sister site, Computer Shopper. As a freelancer, he's written on topics as diverse as Borneo's rain forests, Middle Eastern airlines, and big data's role in presidential elections. A graduate of Middlebury College, Tom also has a master's journalism degree from New York University. Follow him on Twitter @branttom. See Full Bio